exutils.c

libeXosip2-3.0.3.tar.gz

/*
  eXosip - This is the eXtended osip library.
  Copyright (C) 2002,2003,2004,2005,2006,2007  Aymeric MOIZARD  - [e-mail]
  
  eXosip is free software; you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation; either version 2 of the License, or
  (at your option) any later version.
  
  eXosip is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.
  
  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/


#ifdef ENABLE_MPATROL
#include <mpatrol.h>
#endif

#include <osipparser2/osip_port.h>
#include "eXosip2.h"

#if defined(_WIN32_WCE)
#elif defined(WIN32)
#include <WinDNS.h>
#else
#include <netinet/in.h>
#include <sys/socket.h>
#include <arpa/inet.h>
#ifdef HAVE_ARPA_NAMESER_H
#include <arpa/nameser.h>
#endif

#ifdef HAVE_RESOLV8_COMPAT_H
#include <nameser8_compat.h>
#include <resolv8_compat.h>
#elif defined(HAVE_RESOLV_H) || defined(OpenBSD) || defined(FreeBSD) || defined(NetBSD)
#include <resolv.h>
#endif

#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#endif


extern eXosip_t eXosip;

extern int ipv6_enable;

#if defined(__arc__)
#define USE_GETHOSTBYNAME
#endif

#if defined(USE_GETHOSTBYNAME)

void eXosip_freeaddrinfo(struct addrinfo *ai)
{
  struct addrinfo *next;
  while(ai) {
    next = ai->ai_next;
    free(ai);
    ai = next;
  }
}

struct namebuf {
  struct hostent hostentry;
  char *h_addr_list[2];
  struct in_addr addrentry;
  char h_name[16]; /* 123.123.123.123 = 15 letters is maximum */
};

static struct addrinfo *osip_he2ai(struct hostent *he, int port, int protocol)
{
  struct addrinfo *ai;
  struct addrinfo *prevai = NULL;
  struct addrinfo *firstai = NULL;
  struct sockaddr_in *addr;
  int i;
  struct in_addr *curr;

  if(!he)
    /* no input == no output! */
    return NULL;

  for(i=0; (curr = (struct in_addr *)he->h_addr_list[i]); i++) {

    ai = calloc(1, sizeof(struct addrinfo) + sizeof(struct sockaddr_in));

    if(!ai)
      break;

    if(!firstai)
      /* store the pointer we want to return from this function */
      firstai = ai;

    if(prevai)
      /* make the previous entry point to this */
      prevai->ai_next = ai;

    ai->ai_family = AF_INET;              /* we only support this */
	if (protocol == IPPROTO_UDP)
		ai->ai_socktype = SOCK_DGRAM;
	else
		ai->ai_socktype = SOCK_STREAM;
    ai->ai_addrlen = sizeof(struct sockaddr_in);
    /* make the ai_addr point to the address immediately following this struct
       and use that area to store the address */
    ai->ai_addr = (struct sockaddr *) ((char*)ai + sizeof(struct addrinfo));

    /* leave the rest of the struct filled with zero */

    addr = (struct sockaddr_in *)ai->ai_addr; /* storage area for this info */

    memcpy((char *)&(addr->sin_addr), curr, sizeof(struct in_addr));
    addr->sin_family = he->h_addrtype;
    addr->sin_port = htons((unsigned short)port);

    prevai = ai;
  }
  return firstai;
}

/*
 * osip_ip2addr() takes a 32bit ipv4 internet address as input parameter
 * together with a pointer to the string version of the address, and it
 * returns a struct addrinfo chain filled in correctly with information for this
 * address/host.
 *
 * The input parameters ARE NOT checked for validity but they are expected
 * to have been checked already when this is called.
 */
static struct addrinfo *osip_ip2addr(in_addr_t num, const char *hostname, int port,  int protocol)
{
  struct addrinfo *ai;
  struct hostent *h;
  struct in_addr *addrentry;
  struct namebuf buffer;
  struct namebuf *buf = &buffer;

  h = &buf->hostentry;
  h->h_addr_list = &buf->h_addr_list[0];
  addrentry = &buf->addrentry;
  addrentry->s_addr = num;
  h->h_addr_list[0] = (char*)addrentry;
  h->h_addr_list[1] = NULL;
  h->h_addrtype = AF_INET;
  h->h_length = sizeof(*addrentry);
  h->h_name = &buf->h_name[0];
  h->h_aliases = NULL;

  /* Now store the dotted version of the address */
  snprintf((char *)h->h_name, 16, "%s", hostname);

  ai = osip_he2ai(h, port, protocol);
  return ai;
}

static int
eXosip_inet_pton (int family, const char *src, void *dst)
{
  if (strchr (src, ':'))        /* possible IPv6 address */
    return -1;                  /* (inet_pton(AF_INET6, src, dst)); */
  else if (strchr (src, '.'))   /* possible IPv4 address */
    {
      struct in_addr *tmp = dst;
      tmp->s_addr = inet_addr (src);    /* already in N. byte order */
      if (tmp->s_addr == INADDR_NONE)
        return 0;

      return 1;                 /* (inet_pton(AF_INET, src, dst)); */
  } else                        /* Impossibly a valid ip address */
    return INADDR_NONE;
}

/*
 * osip_getaddrinfo() - the ipv4 synchronous version.
 *
 * The original code to this function was from the Dancer source code, written
 * by Bjorn Reese, it has since been patched and modified considerably.
 *
 * gethostbyname_r() is the thread-safe version of the gethostbyname()
 * function. When we build for plain IPv4, we attempt to use this
 * function. There are _three_ different gethostbyname_r() versions, and we
 * detect which one this platform supports in the configure script and set up
 * the HAVE_GETHOSTBYNAME_R_3, HAVE_GETHOSTBYNAME_R_5 or
 * HAVE_GETHOSTBYNAME_R_6 defines accordingly. Note that HAVE_GETADDRBYNAME
 * has the corresponding rules. This is primarily on *nix. Note that some unix
 * flavours have thread-safe versions of the plain gethostbyname() etc.
 *
 */
int eXosip_get_addrinfo(struct addrinfo **addrinfo,
                                const char *hostname,
                                int port,
                                int protocol)
{
  struct hostent *h = NULL;
  in_addr_t in;
  struct hostent *buf = NULL;
  char portbuf[10];

  *addrinfo = NULL; /* default return */

  if (port < 0)            /* -1 for SRV record */
	  return -1;

  if (port != -1)            /* -1 for SRV record */
    snprintf (portbuf, sizeof (portbuf), "%i", port);

  if(1 == eXosip_inet_pton(AF_INET, hostname, &in))
    /* This is a dotted IP address 123.123.123.123-style */
  {
	  *addrinfo = osip_ip2addr(in, hostname, port, protocol);
	  return 0;
  }

#if defined(HAVE_GETHOSTBYNAME_R)
  /*
   * gethostbyname_r() is the preferred resolve function for many platforms.
   * Since there are three different versions of it, the following code is
   * somewhat #ifdef-ridden.
   */
  else {
    int h_errnop;
    int res=ERANGE;

    buf = (struct hostent *)calloc(CURL_HOSTENT_SIZE, 1);
    if(!buf)
      return NULL; /* major failure */
    /*
     * The clearing of the buffer is a workaround for a gethostbyname_r bug in
     * qnx nto and it is also _required_ for some of these functions on some
     * platforms.
     */

#ifdef HAVE_GETHOSTBYNAME_R_5
    /* Solaris, IRIX and more */
    (void)res; /* prevent compiler warning */
    h = gethostbyname_r(hostname,
                        (struct hostent *)buf,
                        (char *)buf + sizeof(struct hostent),
                        CURL_HOSTENT_SIZE - sizeof(struct hostent),
                        &h_errnop);

    /* If the buffer is too small, it returns NULL and sets errno to
     * ERANGE. The errno is thread safe if this is compiled with
     * -D_REENTRANT as then the 'errno' variable is a macro defined to get
     * used properly for threads.
     */

    if(h) {
      ;
    }
    else
#endif /* HAVE_GETHOSTBYNAME_R_5 */
#ifdef HAVE_GETHOSTBYNAME_R_6
    /* Linux */

    res=gethostbyname_r(hostname,
                        (struct hostent *)buf,
                        (char *)buf + sizeof(struct hostent),
                        CURL_HOSTENT_SIZE - sizeof(struct hostent),
                        &h, /* DIFFERENCE */
                        &h_errnop);
    /* Redhat 8, using glibc 2.2.93 changed the behavior. Now all of a
     * sudden this function returns EAGAIN if the given buffer size is too
     * small. Previous versions are known to return ERANGE for the same
     * problem.
     *
     * This wouldn't be such a big problem if older versions wouldn't
     * sometimes return EAGAIN on a common failure case. Alas, we can't
     * assume that EAGAIN *or* ERANGE means ERANGE for any given version of
     * glibc.
     *
     * For now, we do that and thus we may call the function repeatedly and
     * fail for older glibc versions that return EAGAIN, until we run out of
     * buffer size (step_size grows beyond CURL_HOSTENT_SIZE).
     *
     * If anyone has a better fix, please tell us!
     *
     * -------------------------------------------------------------------
     *
     * On October 23rd 2003, Dan C dug up more details on the mysteries of
     * gethostbyname_r() in glibc:
     *
     * In glibc 2.2.5 the interface is different (this has also been
     * discovered in glibc 2.1.1-6 as shipped by Redhat 6). What I can't
     * explain, is that tests performed on glibc 2.2.4-34 and 2.2.4-32
     * (shipped/upgraded by Redhat 7.2) don't show this behavior!
     *
     * In this "buggy" version, the return code is -1 on error and 'errno'
     * is set to the ERANGE or EAGAIN code. Note that 'errno' is not a
     * thread-safe variable.
     */

    if(!h) /* failure */
#endif/* HAVE_GETHOSTBYNAME_R_6 */
#ifdef HAVE_GETHOSTBYNAME_R_3
    /* AIX, Digital Unix/Tru64, HPUX 10, more? */

    /* For AIX 4.3 or later, we don't use gethostbyname_r() at all, because of
     * the plain fact that it does not return unique full buffers on each
     * call, but instead several of the pointers in the hostent structs will
     * point to the same actual data! This have the unfortunate down-side that
     * our caching system breaks down horribly. Luckily for us though, AIX 4.3
     * and more recent versions have a "completely thread-safe"[*] libc where
     * all the data is stored in thread-specific memory areas making calls to
     * the plain old gethostbyname() work fine even for multi-threaded
     * programs.
     *
     * This AIX 4.3 or later detection is all made in the configure script.
     *
     * Troels Walsted Hansen helped us work this out on March 3rd, 2003.
     *
     * [*] = much later we've found out that it isn't at all "completely
     * thread-safe", but at least the gethostbyname() function is.
     */

    if(CURL_HOSTENT_SIZE >=
       (sizeof(struct hostent)+sizeof(struct hostent_data))) {

      /* August 22nd, 2000: Albert Chin-A-Young brought an updated version
       * that should work! September 20: Richard Prescott worked on the buffer
       * size dilemma.
       */

      res = gethostbyname_r(hostname,
                            (struct hostent *)buf,
                            (struct hostent_data *)((char *)buf +
                                                    sizeof(struct hostent)));
      h_errnop= errno; /* we don't deal with this, but set it anyway */
    }
    else
      res = -1; /* failure, too smallish buffer size */

    if(!res) { /* success */

      h = buf; /* result expected in h */

      /* This is the worst kind of the different gethostbyname_r() interfaces.
       * Since we don't know how big buffer this particular lookup required,
       * we can't realloc down the huge alloc without doing closer analysis of
       * the returned data. Thus, we always use CURL_HOSTENT_SIZE for every
       * name lookup. Fixing this would require an extra malloc() and then
       * calling struct addrinfo_copy() that subsequent realloc()s down the new
       * memory area to the actually used amount.
       */
    }
    else
#endif /* HAVE_GETHOSTBYNAME_R_3 */
      {
      OSIP_TRACE (osip_trace
                  (__FILE__, __LINE__, OSIP_INFO2, NULL,
                   "gethostbyname failure. %s:%s (%s)\n", hostname, port));
      h = NULL; /* set return code to NULL */
      free(buf);
    }
#else /* HAVE_GETHOSTBYNAME_R */
    /*
     * Here is code for platforms that don't have gethostbyname_r() or for
     * which the gethostbyname() is the preferred() function.
     */
  else {
    h=NULL;
#if !defined(__arc__)
    h = gethostbyname(hostname);
#endif
    if (!h)
	{
      OSIP_TRACE (osip_trace
                  (__FILE__, __LINE__, OSIP_INFO2, NULL,
                   "gethostbyname failure. %s:%s (%s)\n", hostname, port));
	}
#endif /*HAVE_GETHOSTBYNAME_R */
  }

  if(h) {
    *addrinfo = osip_he2ai(h, port, protocol);

    if (buf) /* used a *_r() function */
      free(buf);
  }

  return 0;
}

#endif

#if defined(WIN32) || defined(_WIN32_WCE)

/* You need the Platform SDK to compile this. */
#include <Windows.h>
#include <Iphlpapi.h>

int
eXosip_dns_get_local_fqdn (char **servername, char **serverip,
                        char **netmask, unsigned int WIN32_interface)
{
  unsigned int pos;

  *servername = NULL;           /* no name on win32? */